Unfolding portable hanging cot

ABSTRACT

A portable cot that consists of a tubular framework that supports a cloth bed. The framework and bed are suspended from above by hanging webbing that allows suspension from a single point. The tubular members of the framework are connected together by hinges that allow the framework to folded into a small bundle of tubes.

BACKGROUND

[0001] 1. Field of Invention

[0002] This invention relates to hanging portable cots that are used mainly, but not exclusively, for rock climbing.

[0003] 2. Discussion of Prior Art

[0004] Over the last 30 years, the level of rock climbing has advanced to the point where multi-day ascents of shear rock faces are possible. Very often on these climbs, the rock face is so steep and relentless that there is no place to rest or sleep. At first climbers used hammocks to sleep in, but these are very constrictive around the body and require two points of attachment. Not to mention the rude awakening you could receive if you were to roll out of the hammock in the middle of the night. In order to overcome the shortcomings of hammocks, climbers developed ridged hanging cots, which are commonly referred to as porta-ledges (short for portable ledge). These homemade porta-ledges were usually made from metal tubing and plumbing fittings. Today, one can choose between several commercially available porta-ledges.

[0005] Most existing porta-ledges are constructed basically the same. There are metal tubes that form the perimeter of a rectangular frame. Nylon cloth is then stretched in the frame to produce a flat bed. This bed is then suspended by four or six pieces of webbing which come together to a single point above the cot. The single anchor point makes it easy to hang.

[0006] The problem in designing porta-ledges is in how to make the frame ridged and yet easy to assemble and disassemble. Most current porta-ledges use straight metal frame tubes that plug into each other with sleeve joints. The tubes are joined at the corners by corner pieces that have two holes at a right angle. The frame tubes are plugged into the corner pieces. In total there are six or eight separate pieces of tubing that must be plugged together in order to be assembled. There are several disadvantages to this design:

[0007] a) With up to eight separate frame tubes to plug together, it is difficult to assemble. You can imagine how difficult this can be when you are hanging in midair from the end of a rope. Also it is inevitable that the tube ends are going to get banged around and distorted. When this happens it makes it almost impossible to assemble.

[0008] b) The frame tubes are not fixed from rotating. At the corners, the tubes are free to rotate in the holes. This allows the ledge to twist along its length forming the shape of a potato chip. More than one climber has cursed when they were flipped out of their porta-ledge when it “potato-chipped”.

[0009] c) The only way to make satisfactory corner pieces is to machine them from solid blocks of aluminum. This makes for an expensive and heavy solution to the problem.

[0010] d) There is no good way to fold up the cloth bed and keep the tubes around the perimeter of the bed. Current designs require you to loosen the bed enough so that it can be fold it into several triangles. This is difficult to do while hanging in mid-air and makes for a large bulky package. It's bulky because the cloth is not neatly rolled, but rather folded several times.

[0011] e) The plug in tube design requires that the bed be tensioned after the frame is assembled. This is because it is impossible to slide the tubes in and out of their sleeves when the bed is tight and pulling the tubes together. Not only is this an inconvenient extra step, but it is also an added expense since there has to be a tensioning mechanism on the cloth bed.

[0012] A more advanced porta-ledge design that unfolds practically all by itself is shown in FIG. 2. This advanced design was patented by myself, Neal Saiki in U.S. Pat. No. 5,60,175. The advantage of this porta-ledge is that it unfolds from tubes that are all pivotably connected. Although, this is a very good design, the design still has several disadvantages.

[0013] a) The long side tubes are pivotably supported at their ends. With a person on the bed, there is tremendous bending force placed on the side tubes. The tubes tend to bend inward in an hourglass shape.

[0014] b) Weight is an important consideration and this design is on the heavy side. The end tubes form an “X” shape and are structurally redundant. Also, the side tubes need to be heavy tubing in order to resist the hourglass bending.

[0015] c) The amount of tubing required is greater than the designs with a perimeter frame. Typically, the aluminum tubing used on these porta-ledges is the largest portion of the material costs.

OBJECTS AND ADVANTAGES

[0016] Accordingly, several objects and advantages of my invention are:

[0017] a) to provide a portable hanging cot whose assembly is greatly facilitated by the elimination of close tolerance joints which must be plugged together;

[0018] b) to provide a portable hanging cot whose assembly is very easy to assemble with no loose pieces;

[0019] c) to provide a portable hanging cot which is ridged and that will resist being twisted into a “potato chip”;

[0020] d) to provide a portable hanging cot that is less expensive by keeping the tubing required to a minimum;

[0021] e) to provide a portable hanging cot that can be efficiently folded into a small package.

[0022] f) By reducing the cost, other markets would be opened. An inexpensive portable hanging cot could be used for camping, backpacking, or even for lounging in the back yard.

[0023] g) to provide a portable hanging cot with the capability of folding in the middle in order to allow a person to sit up and have a backrest.

[0024] h) To provide a lighter and more efficient frame structure to reduce weight.

[0025] Further objects and advantages are to provide a portable hanging cot which is simple, inexpensive to manufacture, and easy to learn to use. Still further objects and advantages of my invention will become apparent from a consideration of the drawings and ensuing description.

DRAWING FIGURES

[0026]FIG. 1 shows a perspective view of my invention from a bottom angle.

[0027]FIG. 2 shows a perspective of a prior art porta-ledge.

[0028]FIG. 3 shows a bottom view of my invention.

[0029]FIG. 4 shows an end view of my invention with more detail of the spreader tubes

[0030]FIG. 5 shows a close up of the side tubes

[0031]FIGS. 6A and 6B shows the steps to fold the portable hanging cot into a compact package.

[0032]FIG. 7 shows my invention in the chair mode.

[0033]FIG. 8 shows a version where the suspension locks out the spreader bars.

[0034]FIG. 9 shows a version where there are three spreader bar assemblies.

LIST OF REFERENCE NUMERALS IN DRAWINGS

[0035] 10 anchor loop 11 suspension assembly 11a middle upper suspension 11b middle lower suspension line line 12 side tube assembly 12a side tube 12b side hinge axle 12c side hinge 13 spreader tube assembly 13a spreader tube axle 13b spreader tube 13c spreader hinge 13d spreader hinge axle 14 bed

[0036] Description—FIGS. 1, 3, 4, 5, and 7, 8, 9

[0037] A typical embodiment of the unfolding portable hanging cot is illustrated in FIG. 1. The cot can be segregated into three general assemblies: a metal tube frame assembly, a bed 14 and lastly a suspension assembly 11.

[0038] In this embodiment, the frame assembly is made up of eight sections of metal tubing. Aluminum tubing being the preferable material due to its high strength to weight ratio and corrosion resistance.

[0039] The side tube assemblies 12 of the frame consist of two frame side tubes 12 a running lengthwise in the longitudinal direction. The side tubes are made from two sections of tubing of approximately equal length and are connected end to end by a side hinge 12 c and two side hinge axles 12 b. The side hinges allow the side tubes to rotate up to 180 degrees from each other. The hinges are aligned to allow the side tube outside ends to rotate upward.

[0040] The spreader tube assemblies 13 are oriented perpendicular to the side tubes in the transverse direction. The spreader tube assemblies are connected to the side tube at the approximate midpoint of each side tube. Their function is to spread the side tubes apart and tension the cloth bed. FIG. 4 shows the spreader tube assembly in detail. The spreader tube assemblies consist of: spreader tube axles 13 a, spreader tubes 13 b, a spreader hinge 13 c and spreader hinge axles 13 d. A spreader hinge connects two spreader tubes end to end. The hinge is aligned to rotate in the horizontal plane. The outside ends of the spreader tube assembly are pivotably connected to the side tubes. The spreader hinge allows slightly more than 180 degrees of movement in order to cause the spreader tube assembly to lock when the hinge swings past straight and keep the bed under tension. The edge view in FIG. 4 shows that the spreader tubes are aligned to form a slight “V” shape in the vertical plane. This is done so that when the bed deflects, the bed will not rest on the spreader tubes and be uncomfortable.

[0041] The hinges shown on the most preferred embodiments are made with double axles and approximately 180 degrees of movement. However, numerous hinging arrangements could be employed. Single axle hinges with an offset axle could be used instead of the double axles. Flexible hinges could be used. Hinges with locking mechanisms could be used for greater security. The hinging motion of the side hinges does not have to be limited to 180 degrees. The rotation of the spreader tubes could be limited by straps attached to the spreader tubes or a stop on the spreader tube outside pivots.

[0042] A cloth bed 14 is sewn from nylon canvas or a similar material. The long sides are sewn into a tube and are slipped over the side tubes. There is a hole in the sleeves for the side tube hinges. The width and length of the bed can be varied to provide room for more than one person.

[0043] The suspension system has six lines. They are made from six pieces of flat nylon webbing. They support the frame at the four corners and at the side hinges. It is preferable to use webbing since it is easy to sew and can also incorporate adjustable buckles that allow the length of the webbing to be adjusted. The six suspension lines are gathered together at an anchor loop 10 where the ledge can hang from.

[0044] Additional embodiments can be made by changing the suspension system. The nylon webbing can be replaced with round cord. The six suspension lines could be replaced with four suspension lines that attach to the side tubes by a triangular cloth gusset for stability. For a cot that can support two people, additional suspension lines would have to be added to support the middle of the bed.

[0045] The suspension lines could also be routed in such manner to pull on the spreader tubes and cause them to lock out straight as shown in FIG. 8. A middle upper suspension line 11 a would split and connect to the middle lower suspension lines 11 b. Each middle lower suspension line would be attached to a spreader tube. When the porta-ledge is weighted, the tension on the suspension lines would pull the spreader tube open and tension the bed. Such an arrangement would make opening the porta-ledge even more convenient.

[0046] There are other possibilities with regard to the frame and hinging mechanisms. The frame tubes could easily be made from steel, carbon-fiber, or other high strength materials and may be of various cross sectional shapes. The hinges that join the side tubes could be of any number of configurations. Almost any hinge type could be utilized.

[0047] Still more variations could be made from varying the number and location of the spreader tube assemblies. The two spreader tube assemblies could be attached nearer to the outside end or even at the outside end of the side tubes. By attaching the spreader tube assemblies at the outside end of the side tubes, a more conventional rectangular perimeter frame would be formed. Such an arrangement would provide more clearance for the bed sag. The tradeoff being that the bending stress on the side tube would be greater. The use of a third spreader tube assembly as shown in FIG. 9 could also be used. The frame would be even stronger, but unfortunately heavier.

[0048] From the description above, a number of advantages of my unfolding portable hanging cot become evident.

[0049] a) All of the frame tubes are hinged together so that there are no separate pieces. Thus unfolding of the cot very easy and there are no loose pieces.

[0050] b) The tubing required for the frame is minimized.

[0051] c) The design is very light weight.

[0052] Operational-FIGS. 6a 6 b

[0053] The uniqueness of this invention is in how the frame folds up into a very small package with simple hinging mechanisms. I have broken down the folding of the cot into two steps that are described in FIGS. 6a and 6 b.

[0054]FIG. 1 shows the frame in the flat position. The bed is tensioned between the two side tubes by the spreader tubes. The spreader tubes stay in the open because the spreader hinge rotates past 180 degrees and then stops. The bed tension keeps the hinge locked open.

[0055] Before any folding of the porta-ledge can begin, the bed must be unweighted. To start the first fold, the spreader hinges must be pulled outward and over center. The bed tension will then be relieved and the spreader tubes can be folded parallel with the side tubes as shown in FIG. 6a.

[0056] The second fold shown in FIG. 6b is made by lifting the end of the side tubes upward. The folded porta-ledge can then be put into a cylindrical cloth bag for protection.

[0057] From the operational description above, several advantages become obvious.

[0058] a) Folding the frame is a very easy two step process. All on the frame tubes are hinged and easy to fold and unfold.

[0059] b) The arrangement of the hinges causes the frame to be locked into a flat position when weighted. The more weight placed on the bed, the more the side tubes are pulled taught against the suspension lines. Since the side tubes cannot rotate, the frame resists the tendency of existing ledges to “potato chip”.

[0060] Summary, Ramifications and Scope

[0061] Accordingly, the reader will see that the unfolding hanging cot of this invention is a great advancement over traditional designs. The cot can be easily folded into a small circular bundle of tubes. The single hanging point makes it easy and convenient to suspend from almost anywhere. Furthermore, the unfolding hanging cot has the additional advantages that:

[0062] The frame is simple and inexpensive to manufacture.

[0063] The frame is lighter than other designs. By better supporting the side tubes, a more efficient structure is formed.

[0064] Assembling the frame is a quick and easy process since all of the joints are hinged. No trying to align tubes in small holes.

[0065] The frame has the ability to fold in the middle when open and provide a backrest for the user to sit up.

[0066] By making a collapsible cot that is easy to unfold, other markets would be opened. An inexpensive portable hanging cot could be used for camping, backpacking, or even for lounging in the back yard. A great application would be for rescue work where portability and easy of use is of prime concern. The unfolding hanging cot could be easily stored inside a helicopter and lowered on a rope for transporting someone who needs to be transported in a prone position.

[0067] Although the description above contains many specifications, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention. For example, the tubes could be of any cross sectional shape, such as square or rectangular. The suspension system could also take on many forms. The frame could also have additional spreader tube assemblies and the location of the spreader tube assemblies could be varied.

[0068] Thus the scope of the invention should be determined by the appended claims and their legal equivalents, rather than by the examples given. 

I claim: 20 In a hanging cot comprising: a) a rectangular bed of flat material, b) a suspension means which provides support from above, said suspension means comprises of a plurality of thin highly flexible members that come together at the top, c) a pair of side members, said side members are each attached along an opposite edge of said rectangular bed, d) a plurality of transverse member assemblies in which each said transverse member assembly comprises a pair of elongated transverse members, said pair of elongated transverse members are connected end to end by a hinging means, each of the free ends of said transverse member assemblies are pivotably attached to said side member assemblies. f) the improvement wherein the transverse member assemblies will open up and tension said bed when said transverse member assemblies are rotated so that said elongated transverse members are roughly in line with each other. 21 The hanging cot of claim 20 wherein there are two, three, or four of said transverse member assemblies. 22 The hanging cot of claim 21 wherein each side member is comprised of a pair of elongated side members that are connected end by a connecting means. 23 The hanging cot of claim 22 wherein said connecting means is a hinge. 24 The hanging cot of claim 23 wherein said hinging means is aligned to allow said elongated side members to rotate when the bed is open and bend said bed into an angle 25 The hanging cot of claim 24 wherein some or all of said thin highly flexible members have a means for adjusting their length. 26 The hanging cot of claim 21 wherein some or all of said thin highly flexible members have a means for adjusting their length.
 27. In a hanging cot comprising: a) a rectangular bed of flat material, b) a suspension means which provides support from above, said suspension means comprises of a plurality of thin highly flexible members that come together at the top, some or all of said thin highly flexible members have a means for adjusting their length, c) a pair of side members, said side members are each attached along an opposite edge of said rectangular bed and each said side member is comprised of a pair of elongated side members that are connected end to end by a hinging means, d) a plurality of transverse member assemblies in which each said transverse member assembly comprises a pair of elongated transverse members, said pair of elongated transverse members are connected end to end by a hinging means, each of the free ends of said transverse member assemblies are pivotably attached to said side member assemblies. f) the improvement wherein the transverse member assemblies will open up and tension said bed when said transverse member assemblies are rotated so that said elongated transverse members are roughly in line with each other. 28 The hanging cot of claim 27 wherein said hinging means is aligned to allow said elongated side members to rotate when the bed is open and bend said bed into an angle. 29 The hanging cot of claim 27 wherein there are two, three, or four of said transverse member assemblies. 30 In a hanging cot comprising: e) a rectangular bed of flat material, f) a pair of side members, said side members are each attached along an opposite edge of said rectangular bed and each said side member is comprised of a pair of elongated side members that are connected end to end by a hinging means, g) a plurality of transverse member assemblies in which each said transverse member assembly comprises a pair of elongated transverse members, said pair of elongated transverse members are connected end to end by a hinging means, each of the free ends of said transverse member assemblies are pivotably attached to said side member assemblies, said transverse member assemblies will open up and tension said bed when said transverse member assemblies are rotated so that said elongated transverse members are roughly in line with each other. e) a suspension means which provides support from above, said suspension means comprises of a plurality of thin highly flexible members that come together at the top. 31 The hanging cot of claim 30 wherein said hinging means is aligned to allow said elongated side members to rotate when the bed is open and bend said bed into an angle. 32 The hanging cot of claim 31 wherein said thin highly flexible members have a means for adjusting their length. 33 The hanging cot of claim 30 wherein some or all of said thin highly flexible members have a means for adjusting their length. 34 The hanging cot of claim 30 wherein there are two, three, or four of said transverse member assemblies. 